Ignition apparatus



Sept. 15, 1936- K. A. HARMON ET AL IGNIT ION APPARATUS Filed June 15, 1935 3 Sheets-Sheet l INVENTOR ji /r/rzr/lAbnmm/r mm BY 72' Ru e: 6%;

TORNEYS Sept. 15, 193 K. A. HARMON ET AL IGNITION APPARATUS s Sheets-Sheet 2 Filed June 15, 1935 Q. n m A mx N2 1. ml MW) N F C \n g w A Q OQ Q fi Sept. 15, 1936. A, HARMON 2,054,461

- IGNITION APPARATUS Filed June 15, 1935 3 Sheets-Sheet 3 B Emu-Ia: 6 Low:

Yatented Sept. i5, 1936 UNITED STATES PATENT OFFICE IGNITION APPARATUS Kenneth A. Harmon and Terrence G. Louis, West Springfield, Mass., assignors to Wico Electric Company, West Springfield, Mass., a corporation of Massachusetts Application June 15, 1935, Serial No. 26,726

11 Claims. (Cl. 123-179) power plants, and so forth. A typical use is in connection with an automobile and 'such use will suflice as an illustrative example to show the advantages and utility of the invention.

The now prevalent type of ignition apparatus used in automobiles consists of an induction coil, deriving its current from the storage battery, which also supplies current to the starting motor used to crank the engine. This so-called battery ignition system has several disadvantages. An inherent weakness in such a system is that spark current diminishes as the engine speed increases and, on the higher speeds, decreases to such an extent that the efiectiveness of the spark is seriously impaired. Such action occurs because magnetic flux can be built up in the core of the induction coil only during the intervals when the breaker points are closed, and the time length of these intervals diminishes as the engine speed increases. And these intervals at the very high speeds are not sufliciently long to enable the magnetism to build up in the core of the induction coil to the same degree that it can in the longer intervals available on slower engine speeds. Another disadvantage of such system is that it is diflicult, in extreme cold weather, to secure an efiective ignition spark. The difiiculty here is that the heavy load imposed on the starting motor in turning over the cold engine, results in a heavy current being drawn from the battery, whereby there is a severe drop in battery voltage. If, for efimple: thebattery voltage drops down to 2 or 3 volts, the current in the primary of the ignition coil will be seriously reduced below the normal value obtained under a normal voltage of say 6 volts. A further disadvantage of the battery ignition system is the relatively heavy current consumption. Typical battery-ignition coils draw 5 to 6 amperes on 45 starting of the engine (assuming normal battery voltage) and during running of the engine the current consumption is around 4 /2 amperes for the lower speeds and diminishes on higher speeds. This current consumption is not, of course, a constant load and occurs only during the times when the breaker points are closed. However,

in battery-ignition systems the effort is to keep the breaker points closed as long as possible, because the longer they are closed the greater is 65 the flux that can be built up in the core of the induction coil. In typical battery-ignition systems the breaker points will be closed about 70% of the time during which the engine is in opera.-

tion, so that for the greater part of the time' there is this heavy current draw. A further disadvantage of such systems is the relatively rapid wear of the breaker points due to the destructive action of the arcing between the points when they open,-such action increasing as the current flow increases.

The other type of ignition system, formerly used on automobiles but now generally abandoned, is the magneto type. The weaknessof this system is the absence of an effective spark on starting. But the magneto has a very important characteristic, which makes it most desirable for the modern automobiles operating at very much higher speeds than heretofore. This characteristic is that the efiectiveness of the spark increases as the engine speed increases. This same characteristic accounts for the disadvantage of the magneto for ignition on starting but, if this disadvantage can be overcome, then the magneto ofiers the best solution for securing efiective ignition on the very high engine speeds now being used.

The apparatus of this invention combines both of the aforesaid types' of ignition, operating on the battery-energized induction coil principle on starting and on the magneto principle for normal running. Attempts have been made heretofore to combine in an ignition apparatus both the statedtypes of ignition but, in no case, so far as we are aware, has the problem been solved completely and efiectively, so as to be followed up by a commercial development such as to render available a commercially satisfactory ignition apparatus combining the advantages of both the aforesaid systems, notwithstanding the need which has existed and is existing for an apparatus of this sort.

This invention has for its general objects to provide an ignition apparatus which will produce a much better spark on starting of the engine than the conventional battery ignition-system and which will produce an effective spark even under unfavorable conditions, such as that of a partially run down battery'or that where there is a. heavy drop in the battery voltage due to a heavy withdrawal of current by the starting motor in cranking the engine in cold weather; which will produce a much better spark than the conventional battery-ignition system on extremely high engine speeds; in which a reduction in the wear on the breaker points may be efiected beto the second plan of operation is automatically,

eflected and kept entirely out of the control of the operator, with the ends in view of reducing to the barest minimum the time during which current from the battery flows through the primary coil and the breakerpoints; of reducing to a minimum the destructive effects on the breaker points of the then existing heavy current flow through them; and of reducing to a minimum the drain on the battery.

More particularly, the invention has for an object the provision of an ignition apparatus including a magnetizable core with primary and secondary coils thereon, breaker points controlling the primary coil and operating in timed relation with the engine, an energizing coil deriving current from the battery and creating magnetic flux which is distributed to and from the core by engine-driven flux distributers, and an automatic means controlled by the switch of the starting motor for directing battery current through the primary coil and the breaker points, when and only when the engine is being turned by the starting motor, and for disconnecting the battery from the primary coil at all other times to allow the spark to be produced on the magneto principle by the changes in flow of magnetic flux efiected in said core by the action of said flux distributers magnetized by said energizing coil.

Another and important object is to arrange the aforesaid-automatic means so as to effect disconnection of the energizing coil from the battery during operation of the apparatus on the induction coil principle, whereby the magnetization of the core by the flow of battery current through the primary coil, is unopposed by flux produced by the energizing coil.

These and other objects will more particularly appear as the detailed description proceeds and will be pointed out in the appended claims.

The invention will be disclosed with reference to the accompanying drawings, in which:

Fig.1 is a central sectional elevational view of an ignition apparatus embodying the invention;

Fig. 2 is an end elevational view of the breaker point mechanism;

Fig. 3 is a cross sectional view taken on the line 33 of Fig. 1;

Fig. 4 is a fragmentary top plan view, showing the ignition coils,-the cover therefor ."f'having been removed;

Fig. 5 is a view, takensimilarly to Fig/4 except that the ignition coils and their core have been removed to reveal the pole pieces;

Fig. 6 is a. cross sectional view taken on the line 6-6 'of Fig. 1;

Fig. '7 is an end elevational view of the switch unit shown in Fig. 6;

Fig. 8 is a fragmentary cross sectional view taken on the line 8-8 of Fig. 4; and

Fig. 9 is a diagrammatical view showing the various electrical units of the apparatus, with their connections and the complete ignition system formed thereby.

Referring to Fig. 1 of these drawings, the apparatus is contained in a casing I, having a cylindrical bore 2 closed at one end by a head I,

in which asuitable anti-friction bearing 4 is mounted. A removable head 5, held to casing I by cap screws 6, closes the other end of bore 2 and has mounted therein an anti-friction bearing I. Rotatably mounted in these bearings is a shaft 8 adapted to be driven from the engine which the ignition apparatus serves, and usually from the cam shaft. This shaft 8 is made of magnetizable metal. It passes centrally through the coil-9 of an electromagnet and forms a core therefor adapted to be magnetized by the coil when the latter is energized. Coil 9 is stationarily supported in the bore 2 intermediate the ends thereof. Shaft-8 has fixed to it in axially spaced relation two flux distributers Ill and I0, disposed one on each side of the energizing coil 9 of the electromagnet. As shown in Fig. 3, these flux distributers are of like construction but one is angularly spaced from the other. Each is made up of soft iron laminations (Fig. 1) held together as by rivets II, and each includes a plurality (three in the form shown in Fig. 3) of arms radially projecting from the shaft. These radial clamped in axial position against a shoulder I2 by a nut l3, threaded on the shaft. In the form herein shown, each radial arm'of the distributer I0 is angularly spaced from the corresponding arm of distributer III by an angle of 60 degrees.

These flux distributers are adapted to direct flux from the electromagnet to and from a core ll, made up of soft iron laminations, suitably held together as by rivets It. On this core are mounted primary and secondary coils l5 and I8, respectively. The distributers not only make and break a magnetic circuit through this core a plurality of times during each revolution of shaft 8 but, preferably also, effect this result by creating reversals of flux through the core, as will later appear. For these purposes the flux distributers cooperate with pole pieces made up of soft iron laminations and suitably fixed in the casing I and in this instance embedded therein during the process of casting the casing. There are two pairs of these pole pieces (Fig. 5), one pair for each distributor, the members of one -pair being marked l1 and I8 and the corresponding members of the other pair being marked l1 and I8, respectively. The pole pieces I1 and I8 lie in the same transverse plane as the distributer l0 (Fig. 1) and the pole pieces l1 and I8 lie in the same transverse plane as the distributor Ill. The casing I has a flat face [9, approximately tangential to the cylindrical portion thereof and through this face is an opening leading into bore 2 (Figs. 3 and 5). Each pole piece has one end formed with a flat face 20 lying in the plane of said flat face Ill. The other end of each is formed with an'arcuate surface faces 20 of the pole pieces. The core 34 interconnects the bridges 22 and 24 (Figs. 3 and 4) and its ends rest directly on top of the bridges in seats provided for this purpose as shown in Figs. 1 and 3. Clamps 25, one at each end of core l4, are secured to casing I by screws 26 and act to press the core ends tightly against the bridges and the latter tightly against the faces 20 of the pole pieces.

The arms of each flux distributer and the pair of pole shoes, with which it cooperates, are so spaced that when one arm is covered to any substantial extent by one pole piece of a pair, the other arms are entirely out of covering relation with the other pole piece of the pair. And the two distributers are angularly spaced so thatwhen one arm of one, as I0, is covered by a pole piece, as l8, one arm of the other, as I, is covered by the opposite pole piece, as Il'. Thus, with the distributers positioned as described, flux will then flow from the distributor of north polarity, say [0, through pole piece l8 and bridge 24 to the right hand end (as viewed in Fig. 3) of core l4 and return from the opposite end of the core through bridge 22 and pole piece IT to distributer l0. Flux cannot at this time pass from pole piece H to distributer I'll nor from pole piece I 8' to distributer l0. On continued rotation of shaft 8, that arm of distributor I0 which was covered by pole piece [8 moves out of covered relation therewith and a succeeding arm becomes covered by pole piece I! andthe arm of distributer l0, which was covered by pole piece I'I' moves ahead and becomes covered by pole piece l8. Flux then flows from distributer I0 through pole piece l1 and bridge 22 to the left hand end of core I4 and returns from the opposite end of the core through bridge 24 and pole piece l8 to distributer l0. Flux cannot then pass from pole piece H to distributer i0 nor from pole piece IE to distributer l0. Thus, each arm of each distributer cooperates successively with its pair of pole pieces to establish magnetic flux in core l4 first in one direction and then in the opposite direction. Three times during each revolution of shaft 8, magnetic flux is established in one direction through core l4 and three times during each revolution flux is established in the opposite direction in core M. The result is that flux is built up in the core six times during each revolution but alternately in opposite directions so that the transition is from a maximum in one direction to a maximum in the other direction, whereby a large effective flux change can be utilized in the core to induce a current in the coils thereon. The reversal of flux in core l4, while important and preferred, is not essential to the broader features of the invention.

The arrangement described is suitable for a six cylinder engine in which the cam shaft, travelling at one-half the crankshaft speed, drives the shaft 8. It is contemplated that the arrangement may be varied to suit engines having a greater or less number of cylinders by varying the number of arms on the flux distributer and the angular extent of the arcuate surfaces 2| of the several pole pieces.

The casing l is, of course, made of non-magnetic metal, such as aluminum for example. Cooperating with the casing l to enclose the core l4 and coils l and I6, is a cap 21 of insulating material such as bakelite. This cap rests on the surface IQ of casing I and is secured thereto by screws 28. The cap 21 has mounted therein a metallic socket 29 to which one end of a high tension wire 3!) is connected. This socket carries a contact finger 3! which presses against the high tension terminal 32 of the secondary eoil Hi. The other terminal of coil I6 is grounded in any suitable way.

A suitable breaker point mechanism (Fig. 2) is mounted on the' outer face of head 3 and operated by a cam 3i mounted on the outer end of shaft 8. This cam is clamped against one end face of the rotatable race of ball bearing 4 by a screw 32, threaded into shaft 8, the head of the screw being received in the counterbored end of the cam as shown. The stationary breaker point 33 is carried by a metallic bracket 34 fixed to head 3 and thereby grounded. The movable breaker point 35 is fixed to one end of an arm 36 of insulating material. This arm is pivoted intermediate its ends on a stud 31 fixed to head 3 and the other end of the arm serves as a follower to be engaged and moved by cam 3!. A flat spring 38 is secured at one end to arm 36 in electrical contact with point 35 and at the other'end by a screw 39' to a block 39 of insulation, fixed to head 3. This spring tends to hold the breaker points engaged and also to electrically connect the terminal 39' to the movable breaker point 35. The bracket 34 is pivoted on stud 31 but is normally held against turning on this pivot by a screw 40 which clamps the bracket to head 3. The bracket is slotted to receive screw 40 and the slot enables'a limited degree of swinging movement of the bracket, when screw 40 is loosened, for the purpose of adjusting the breaker point 33 relatively to its companion breaker point 35. An eccentric stud 4|, mounted-to turn in head 3, engages in a slot in bracket 34, and when this stud is turned the bracket will be swung on its pivot. The cam 3|, as shown, is of hexagonal cross sectional shape and its six projections successively engage and move the arm 36 and cause the breaker points to separate six times during each revolution of shaft 8. The breaker point mechanism is given merely as an illustrative example of one suitable form and any other suitable form may be used as desired.

On the outer face of head 3 and encompassing the breaker point mechanism described is a circular flange 42 (Fig. 2) on which is seated a distributer cap 43 (Fig. 1) of insulating material.

Spring clips 44 (Fig. 2), each pivoted to and.

between a pair of lugs on flange 42, engage in recesses in cap 43 (Fig. 4) in the usual way and hold the cap to its seat on flange 42 against axial and turning movement. The cap (Fig. 1) has a. circular series, six in this case, of contacts 45 each connected to an exterior binding screw 46. To the screws 46 are connected the high tension wires 41 leading to the spark plugs s of the engine (see Fig. 9). .The case also carries a central terminal 48 to which the lead wire 30 from the secondary coil [6 is connected. This terminal on its inner end carries a spring pressed plunger 49 which engages the inner end of a. conducting strip 50 mounted on the distributer brush arm 5|, The brush arm, which is of insulating material, telescopes over the outer end of the breaker point cam 3| and has a projection 52 fitting in a recess in the cam to effect an operable driving engagement. The outer end of strip 50 is movable successively into close proximity to the contacts 45 and thus the high tension current is distributed in proper order to the several spark plugs s.

Variations in the timing of the spark may be effected in anydesired way. All that is neee sary is to turn the breaker point mechanism rela-, tively to its operating cam 3i and this may be done either by turning the casing I relatively toshaft 8 or by turning shaft 8 relatively to the casing. A timing adjustment of the breaker point mechanism results in a corresponding adjustment of the distributer because the distributer brush is fixed to the cam 3| and. the dlstributer cap is fixed to the head 3 which carries the breaker points.

In Fig. 1, we have shown a cup-shaped casing 58, secured in abutting relation with the head 5, to casing I by the described screws 8. The casing 53 houses a centrifugal governor of well known 'form for advancing the shaft 8 relatively to the shaft which drives it,-in this case a shaft 54 mounted in a hub-like extension 55 of casing 53. Fixed to the inner end of shaft 54 is a member 58 to which are pivoted at diametrically opposite points on studs 51 two weights 58, which at relatively high speeds fly outwardly. Two pins 59 engaged one with each of these weights are fixed to a plate 88, secured as indicated to one end of shaft 8. The arrangement is such that as the weights 58 fly outwardly they turn shaft 8 ahead of shaft 54 and effect an automatic advance of the spark. It is not thought necessary to describe this device in detail as it is not in itself a feature of novelty and is mentioned herein simply to show that provision may be made for an automatic spark advance mechanism.

The hub 55 is intended to fltinto the usual socket provided in the engine crankcase and is usually mounted therein for limited turning movement, whereby the casings 53 and I may be turned by any suitable means, automatically or otherwise, to secure variations in the timing of the spark.

-Either or both forms of spark advance means may be used as desired. Within the described socket is located one end of an engine driven shaft and the shaft 54 is shaped, as indicated, for a coupling engagement with such engine driven shaft, when hub 55 is inserted in said socket.

Referring to Fig. 6, the casing I, at a point near the head 3, is built out at diametrically opposite locations into generally rectangular form, to provide two opposed chambers 82 and .is held to such wall by a nut 81.

83 of rectangular cross sectional shape, leading outwardly from bore 2. In the chamber 82 is mounted a suitable condenser 84 which in this case is of the cartridge type having screw threaded terminals 85 and 88 extending axially from opposite ends thereof. The terminal 85 passes through the lower wall of the chamber 82 and 85 is thereby grounded to and the condenser supported from the casing I.

Fixed by screws 88 to casing I is a strip 89 (Figs. 4 and 6) of insulating material extending parallel with but slightly below the surface I9. This strip has three binding posts 18, II and I2 thereon. The terminals of the primary coil I5 are connected by wires I3 and I4 (Fig. 4) to the posts 1| and 12, respectively. A wire |5 (Fig. 6) connects the insulated terminal 88 of the condenser to post 12 and a wire 18, extending through head 3, connects the terminal 88, and thus the insulated breaker point 35, to post 12.

The magnet coil 9 (Figs. 1 and 3) is mounted within a short cylindrical casing 11 of insulating material, including'a cover 18. This casing has diametrically disposed lugs 19 (Figs. 1 and 3), projecting radially outward and engaged in The terminal grooves 88 formed in the bore 2 of casing I and paralleling the axis thereof. The casing 11 may thus slide in an axial direction in, the casing I and the grooves 88 extend from the open end of bore 2 to a point about midway thereof. In the assembling operation, shaft 8 with the casing II loosely mounted thereon between the rotors, is slid into the bore 2 with the lugs 19 riding in grooves 88. After the rotor is in place the easing 11 is pushed in until the lugs I9 abut the ends of the grooves 88, as shown in Fig. 1, whereby the casing 11 will be properlylocated between the rotors and in position to be fastened in place. This casing 11 is fastened by cap screws 8I and 82 (Fig. 3) which extend through casing I at diametrically opposite points and. thread into metallic inserts 83 (see also Fig. 8) molded in the casing. "The terminals of the magnet coil 9 are connected one to each insert 83. The screws 8| and 82, which are insulated from casing I by washers 84, thus hold the casing ll in place and also serve as terminals for the magnet coil.

The chamber 83 control switch which is mounted on the inner face of a plate 88, secured by screws 81 to the casing to close the outer end of the chamber. This switch is operated under remote control by an electromagnet, including a magnetic core 88, a magnet coil 89 thereon and an armature 98, pivoted to plate 88. This electromagnet is secured to a bracket 85 fixed to plate 88 by bolts 85'. One terminal of coil 89 is grounded to bracket 85 and the other is connected by a wire 89' to a terminal bolt 9| which passes through and is insulated from bracket 85 and plate 88. The armature actuates through the intermediary of slidable push rods 92 of insulating material, two spring fingers 93 and 94 (Fig. 'l) which are fixed to bracket 85 by the bolts 85' and which are insulated from the bracket as indicated. The finger 93 is normally engaged with a stationary and grounded contact 95 and becomes disengaged therefrom when the magnet coil 99 is energized. The finger 94 likewise normally engages a stationary and grounded contact 98 but, when it is moved on energization of the magnet coil 89, it not only becomes disengaged from contact 98 but also engaged with a contact 91, carried by a finger 91, fixed to bracket 85 by the terminal bolt 9I and insulated from the bracket as indicated. The finger 94 is connected by a wire 98 to the described binding post 'II and thus to one terminal of the primary coil I5. The finger 93 is connected by a wire 99 to the binding post 18 and a wire I88 leads from this post to a terminal I8I, mounted on and insulated from a plate I82 which is secured by screws I83 to casing I and closes the outer end of chamber 82. The terminal I8I is connected by an insulated conductor I84 (Fig. 4) outside the casing I, to the terminal 82 of the magnet coil I.-

The work accomplished by the swatch unit just described, as well as the operation of the apparatus, will best be understood from the diagram' in Fig. 9 which shows all the electrical elements above described and their connections with other elements used in conjunction with the engine. In this figure M is the electric starting motor used for cranking the engine; S is the usual switch for the starting motor, which switch is normally held open automatically and is closed by the operator only for short intervals. B is the storage battery, usually of six volts. One side of the battery is grounded and the other side is connected by a wire I88 to one terminal of (Fig. 6) serves to house a' I that switch S. The other terminal of switch S is connected by a wire I91 to one side of motor M and the other side of motor M is grounded. The usual ignition switch is shown at I and one terminal of it is connected by a wire I98 to the ungrounded side of battery B and the other terminal thereof is connected by a wire M9 to the terminal 8! of magnet 9. A wire H9 leads from wire ID! to the terminal 9| and thus to the magnet coil 89, whereby this coil will be energized from battery B when and only when the starter switchis'hlosed. The other electrical connections have alr'eady been described.

In operation, the operator proceeds in the same manner as is usual with battery ignition systems. That is, he closes the ignition switch I and then presses on the starter switch S to close it and hold it closed until the engine has been started by motor M. The closing of the ignition switch in this case serves only to close a circuit through the magnet coil 9. This circuit is as follows;from battery B by wires I06 and I08 to and through switch I, thence by wire I99 to terminal 8| of coil 9, thence from coil terminal 92 by way of wire I04 to terminal HH and by way of wire I99 to terminal 10, thence by wire '99 to switch finger 93 and contact 95, and by the ground back to the battery. The closing of the starter switch S serves, in addition to its usual and normal purpose, to establish the starting ignition circuit. It causes the energization of the magnet coil 89 and insures the deenergization of magnet 9. Current flows from wires I06, I01 and H to terminal 9| and thence by wire 89' to coil 89 and from the coil by way of the ground connection back to the battery. On energization of coil 89, the armature 99 is pulled in by the then magnetized core 88 and the fingers 93 and 94 are moved from their normal positions illustrated. Movement of finger 93 simply opens up the circuit to magnet 9. Movement of finger 94 first breaks the ground connection 96 of the primary coil 15 and then closes a circuit from the battery B through the primary coil. The primary coil l5 and the breaker points are included in series in a normal running circuit which may be traced as follows:from the fixed and grounded breaker point 33 to the movable breaker point 35, thence by spring 38 to terminal 39' and by way of wire 16, terminal 12, wire 14, to the primary coil l5, and thence by wire 13, terminal H, wire 98, switch finger 94, and contact 96 to the ground. The movement of finger 94 by the magnet 89 breaks the last named ground.

connection of the primary circuit and extends such circuit as follows:-through contact 91, finger 91 to terminal 9 I, thence by wires I Ill and ID! to switch S, and thence by wire I96 to the battery B and to the ground. This is the starting circuit and exists only for the short intervals during which switch S is held depressed. At such times, current from battery B will flow through the primary coil l5 whenever the breaker points 33 and 35 are engaged. The coils l5 and I6 then function on the same principle as the usual battery ignition coil. And during this interval, the electromagnet 9 is deenergized so that no magnetic flux from that source willbe present in core l4, to interfere with the magnetization of the core by battery current flowing through the primary coil l5. However, the instant that switch S is released, magnet 89 is deenergized and the battery is cut off from the primary coil by the disengagement of finger 94 from contact 91 and such finger immediately engages the contact 96 to reestablish the normal primary circuit. Also, finger 99 engages contact 95 and reestablishes the circuit from the battery through coil 9. The apparatus then functions as a magneto,the distributers l9 and i9 creating flux changes in core l4 and causing the generation of current in the windings l5 and B6. The same breaker points control both the starting and running circuits of the apparatus.

In the operation of the apparatus as a magneto, flux from the electromagnetic source 9 is allowed to build up in core 14 under conditions as favorable as possible. That is, the primary circuit is kept open for relatively long intervals to allow the fiux to build up in the core without the opposing influence of a short circuited primary coil. The breaker points, in the form of apparatus herein disclosed, complete one cycle of operation in one-sixth of a revolution of shaft 8 or in 60 degrees. During this interval, the breaker points are closed about two-thirds of the time and open only about one-third of the time. In Fig. 3, the flux distributers are shown in the positions which they occupy at the moment the breaker points open. Flux will then build up in core l4, flowing from right to left, the circuit being from the nearly vertical distributer arm I0 through pole piece l8, bridge 24, core l4, bridge 22, pole piece. H to that distributer arm III which in Fig. 3 lies immediately to the left of the aforesaid arm ID. The breaker points remain open until these two arms l9 and I9 become completely covered by their respective pole pieces l8 and I1 and until these arms start to leave such pole pieces. Then the breaker points close and the then short circuited primary coil tends to resist a change of flux in core I4. This condition continues until the aforesaid two arms In and [9' have moved far enough away from the forward edges of their respective pole pieces to create substantial gaps, such as those shown at g and g in the magnetic circuit. Then the breaker points again open and a sudden change of flux occurs in core l4. But this change is not simply from a maximum to zero but from a maximum in one direction to zero and beyond to approach as near as possible to a maximum in the other direction. For at the time of the opening of the breaker points, the aforesaid arm ID has moved into partially covered relation with pole piece l8 while a succeeding arm II] has moved into partially covered relation with the pole piece I1. Flux then flows from left to right in core l4 andthus in the opposite direction to the flow of fiux previously established. Hence, in the magnetic change, a reversal of flux is secured. Such a flux change in core I4 is effected six times during each revolution of shaft 8 to produce an ignition spark in the usual manner. This \gives the three sparks per revolution'required for the six cylinder engine.

.It should be particularly noted that the primary coil I5 is not the same as the primary coil used in the conventional battery ignition system, although it operates on the same principle during the interval when battery current is directed through it. The coil is primarily a magneto coil and has fewer turns of larger wire and much less resistance than the average primary of an induction coil. The coil I5 is purposely designed to produce good sparking at low engine speeds on the magneto principle of operation. While the usual primary of an induction coil could be'used as the primary of the magneto, its resistance, which is usually about four times as great as that of coil I 5, would be too great to allow good sparking to be produced when the engine is operating at low speeds, especially where as here, the fluxdistributers are rotating slower than the engine at half the speed of its crankshaft. Thus, the primary coil Iis essentially a magneto primary anddoes not have the same characteristics as the primary of an induction coil. And due to this fact, an important advantage is secured. Because of the low resistance of coil IS an adequate flow of current through it can be secured even with a partially depleted battery or with a nondepleted battery which is subjected to a heavy voltage drop due to an unusual starting load. As an illustrative example and without setting up limitations, the coil I5 may have a resistance such that it will draw six amperes at three volts or half the usual battery voltage. This is as great a current as the average primary of an induction coil would draw from the battery at six volts. Thus, the coil I5 is enabledto produce better ignition, under the unfavorable battery conditions named, than the conventional battery ignition system and under normal conditions it produces a better spark due to the heavier current flow, say 12 amperes. In this way, the problem of a good spark at starting, even under unfavorable conditions, has been solved and a better starting spark under all battery conditions is'efiected than in the conventional battery j ignition system.

The use of such a heavy current flow would be fatal if the flow were continued forany great length of time. The heavy arcs produced at the breaker points and the consequent burning of them would soon destroy them. Therefore, it is imperative that the time during which such heavy currents flow across the breaker points, be reduced to the barest minimum. It cannot safely be left'to the judgment of the operator when to change from battery ignition tomagneto ignition. At best, he would needlessly prolong-the interval during which the apparatus operates on the induction coil principle and a careless operator might forget to make the change with the result that the breaker points would soon be destroyed. Then the system would be condemned as unsuitable. Therefore, the provision of the automatic means for predetermining and limiting the times of'operation on the induction coil principle is a most important factor and, it is believed, the key to success in the production of a commercially successful ignition apparatus of the type in which the induction coil principle and magneto principle are combined. Such automatic means, controlled by the starter switch, insures the shortest possible time for heavy current to pass through the primary coil and breaker points; it minimizes the destructive effects on the breaker points; it reduces the drain on the battery; and it offers at the same time the simplest and easiest form of control, requiring no attention from the operator and no change other than running a wire, such as llll, from the starter switch to the terminal 9| of the ignition apparatus.

In fact, the apparatus requires no substantial change for its installation. If originally installed in the automobile, one puts the ignition unit in the place usually occupied by the timer and distributer unit. After that, the wire from the ignition switch I is led to the terminal 8| of the energizing coil S instead of to the usual ignition coil.- The only additional wiring is the wire H0 above described.

The use of the ignition apparatus of this inon starting and about 4 amperes on medium engine speeds, dwindling to lesser values at the higher engine speeds with resulting loss in effectiveness of ignition. Of course, the current used forthe energizing coil is a constant load during operation of the engine, whereas in the conventional battery ignition system, the current flows only while the breaker points are closed. But it is essential in a battery ignition system that the breaker points be closed as long as possible in order to get as much time as possible for the building up of flux and usually they are closed about 10% of the time. substantial saving in battery current through the use of this apparatus.

The invention effects a reduction in the wear on the breaker points over that resulting from the use of the conventional battery ignition system. In order for the induction coil of the last named system to produce a reasonably good low speed spark and a reasonably good high speed spark, it is necessary to pass a much higher current through it at medium speeds than would otherwise be necessary and than is used in the present apparatus. Consequently, the larger amount of current flowing across the breaker points during the intervals of medium engine speed operation, and these are usually the longer intervals of engine operation, results in more rapid burning of the breaker points and lessened length of life. Fiu-thermore, the condenser which is employed to reduce arcing at the breaker points, cannot so effectively accomplish its intended purpose in the battery ignition system as in the magneto. A condenser designed to function well on high speeds will not function well on low speeds and vice versa. The diflerence in current flow under these two conditions is too great to allow one condenser to properly work under both conditions. But in magneto operation there is not such a wide differential and it is a fact that one condenser will function much more effectively throughout the speed range than in a battery ignition system, and this fact means lessened wear and longer life of the breaker points. While the condenser does not function as well during periods of battery operation, these periods as above set forth, are purposely made exceedingly short so that the wear occurring from this cause is so reduced as to be negligible.

The apparatus of this invention produces a better spark at high engine speeds. The more rapid the engine speed, the more rapid is the flux change produced by rotation of the distributers I ii and I0 and the rate of change of flux as well as the amount of change is a factor in the production of the spark. Then,.the flux is built up in the core H under the most favorable conditions,

7 via, while the breaker points are open and thus without the opposing choking influence of a shortcircuited primary. With the conventional battery ignition system, time is an important factor in the establishment of flux in the core of the induction coil. Magnetization occurs only when the breaker points are closed and builds up rela- Therefore, there is aaosg ei tively slowly. Naturally, as the engine speed increases, less and less time is available for the building up of flux, wherefore the current falls off and poo-r sparking results. In contradistinction to the practice employed in conventional battery ignition systems of keeping the breaker points closed as long as possible, the practice here is to keep them open as long as possible and close them only for short intervals to hold the flux while a gap is created in the magnetic circuit preliminary to the ensuing break.

The apparatus is a compact, light weight unit,

complete in itself and requiring only two wire connections to the battery, as above described. It utilizes an energizing coil in place of the more expensive magnets of cobalt steel which would be necessary to use to secure a degree of compactness approaching that herein disclosed. But the use of the coil is important for the reason that the action of the magnetic source can be discontinued during periods of induction coil operation so as not to interfere therewith, whereas the harmful action of permanent magnets at such periods cannot be so easily avoided. It is deemed important that the coil 9 be stationary. Use of slip rings is avoided as well as their initial cost and the troubles in operation likely to arise from their use. The weight of the rotating parts is also reduced by not mounting the coil 9 on the shaft 8 and it is important to keep the weight of rotating parts as low as possible and reduce the wear on the moving parts. The pole piece arrangement, with the bridge pieces and the core which interconnects them, is important in that it enables the use of flux distributers of simple and inexpensive form and of a form which can be made up of laminated soft iron stampings as is desired for their excellent magnetic qualities. Specially shaped and expensive forgings, which are also less desirable because of their poorer magnetic qualities, are avoided.

The invention thus provides an improved ignition apparatus, characterized in that it is adapted to more efficiently utilize the battery current and secure better ignition with a less consumption of current than in a conventional battery ignition system and characterized also in that it is capable of producing a better starting spark and a better spark at high speeds and a good starting spark under unfavorable battery conditions where the said conventional system would fail. The invention also enables a reduction in the drain on the battery and in the wearon the breaker points to be effected over the aforesaid system.

The features disclosed herein and relating to dual ignition apart from coordination with the starter switch form the subject matter of and are claimed in a divisional application filed October 11, 1935 under Serial No.'44,566. The features disclosed herein and relating to the magneto construction form the subject matter of and are claimed in a divisional application filed October 11, 1935 under Serial No. 44,567.

What we claim is:

1. The combination with an internal combustion engine, having a starting motor, a battery, a starter switch, a circuit including said motor, battery and switch, said switch being operable when closed to direct current from the battery through the motor; of a magneto including primary and secondary coils, and enginedriven means for periodically eiiecting changes of magnetic flux through the primary coil in-timed relation with ,the engine, a second circuit normally free from connection with the first circuit and including said primary coil, engine driven means for periodically opening and closing said second circuit in timed relation with the engine whereby ignition current may be produced in the secondary coil on the magneto principle, and means operable by the closing of the starter switch and effectiveonly during the interval when such switch is closed to connect the first and second circuit anddirect current from the battery through said primary coil and circuit breaking means to induce ignition current in the secondary c'oil on the induction coil principle.

2. The combination with an internal combustion engine, having a starting motor, a battery and a starter switch operable when closed to direct current from the battery through the motor; of a magneto including primary and secondary coils, a core therefor, an electric circuit for the primary coil, an electromagnet energized from said battery for producing flux, engine driven means for periodically making and breaking a magnetic circuit from the electromagnet through said core, and engine driven means for periodically opening and closing said primary circuit, whereby ignition current may be produced in the secondary coil on the magneto principle, and means operable by the closing of the starter switch and effective during the interval when said switch is closed to disconnect the battery from said electromagnet and direct current from the distributing members connected to the magnet.

core and driven by the engine, means driven by the engine to periodically open and close the primary circuit, said members cooperating with the first named core to establish flux through said primary coil during its open circuit intervals, and switch means for changing said primary circuit to include said battery, whereby battery current may be directed through the primary coil during its closed circuit intervals, the operation of the last named means being initiated by the closing of the starter switch and the duration of its operation determined by the length of time that the starter switch is closed.

4. Ignition apparatus for an internal combustion engine, having a starting motor, a battery to energize the motor and a starter switch operable when closed to direct current from the battery to the motor; comprising a soft iron core, primary and secondary coils on said core, a circuit including said primary coil, an electromagnet including a core and'a 'coil in circuit with said battery and effective to magnetize the core, flux distributing members connected to the magnet core and driven by the engine, means driven by the engine to periodically open and close the primary circuit, said members cooperating with the first named core to establish flux through said primary coil during its open circuit intervals, and switch means forinterrupting the circuit to and discontinuing the action of said electromagnet and for simultaneously changing said primary circuit to include said battery, whereby battery current may be directed through the primary coil during its closed circuit intervals, the operation of the last named means being initiated by the closing of the starter switch and the duration of its operation determined by the length of time that the starter switch is closed.

5. An ignition apparatus for internal combustion engines, comprising, a soft iron core, primary and secondary coils on said core, an electromagnet including a core and a coil effective when energized to magnetize the core, a battery in circuit with the last named coil to energize the same, flux distributing members connected to the magnet core and adapted to be driven by the engine, :said members cooperating with the first named core to alternately make and break a magnetic circuit from said electromagnet through the first named core and said primary coil, cooperating and relatively movable breaker points, a circuit including said points and primary coil and adapted to be opened and closed by the opening and closing of said points, means operated in timed relation with the flux distributing members for opening and closing the breaker points, a motor for starting said engine, a control switch for the motor, and means operable by the closing of said switch and eilfective only while said switch is closed to change said primary circuit to include said battery, whereby battery current will be directed through the primary coil when the breaker points are closed and ignition sparks will be produced by the secondary coil on the induction coil principle.

6. An ignition apparatus for internal combustion engines, comprising, a soft iron core, primary and secondary coils on said core, an electromagnet including a core and a coil effective when energized to magnetize the core, a battery in circuit with the last named coil to energize the same, flux distributing members connected to the magnet core and adapted to be driven by the engine, said members cooperating with the first named core to alternately make and break a magnetic circuit from said electromagnet through the first named core and said primary coil, cooperating and relatively movable breaker points, a circuit including said points and primary 'coil and adapted to be opened and closed by the opening and closing of said points, means operated in timed relation with the flux distributing members for opening and closing the breaker points, a motor for starting said engine, a control switch for the motor, and means operable by the closing 01' said switch and efiective during the interval when said switch is closed for interrupting the circuit to said electromagnet and for changing said primary circuit to include said battery, whereby battery current will be directed through the primary coil when the breaker points are closed and ignition sparks will be produced by the secondary coil on the induction coil principle.

7. The combination with an internal combustion engine, having'a starting motor, a battery having one terminal grounded and a starter switch operable when closed to direct current from the battery through the motor, of an ignition unit adapted to be mounted on the engine and comprising a soft iron core, primary and secondary coils on said core, a circuit including said primary coil, an electromagnet including a core and a' coil eilfective to magnetize the core, flux distributing members connected to the magnet core and driven by the engine, means driven by the engine to periodically open and close the primary circuit, said members cooperating with the first named core to establish flux through said primary coil during its open circuit intervals, casing means in which all the aforesaid elements of the unit are mounted, switch means housed within said casing, an electromagnet for actuating said switch means, a connection from the battery to one terminal of said electromagnet coil and a connection from the motor side of the starter switch to one terminal of the electromagnet of said switch means, the other terminal of each electromagnet being grounded in said casing, the electromagnet of said switch means being energized when and only when the starter switch is closed and operating the switch means to direct.

current from the battery through said primary coil and simultaneously interrupt the circuit from the battery to the first named electromagnet coil.

8. The combination with an internal combustion engine, having a starting motor, a battery having one terminal grounded and a starter switch operable when closed to direct current from the battery through the motor, of an ignition unit comprising a soft iron core, primary and secondary coils on said core, a circuit including said primary coil and closed by grounding,

, an electromagnet including a core and a coil eifective to magnetize the core, flux distributing members connected to the magnet core and driven by the engine, means driven by the engine to periodically open and close the primary circuit, said members cooperating with the first named core to establish flux through said primary coil during its open circuit intervals, a pair of normally closed switches each including a grounded terminal, an electromagnet -i'or simultaneously opening the switches, the ungrounded terminal of the battery being connected to one terminal of the firstnamedelectromagnet coil and the other terminal of the latter being connected to one 01' said switches, one terminal of the second named electromagnet being connected to the motor side oi. the starter switch and the other terminal grounded, the other of said pair of switches being connected in said primary circuit, whereby when said starter switch is closed said pair oi. switches are opened by the last-named electromagnet, and

a contact connected to the motor side of the starter switch and adapted to be engaged by and when the second-named of said pair oi. switches is opened for directing battery current through said primary coil.

9. In an ignition system for internal combustion engines, the combination of a battery, a circuit therefor, an ignition apparatus of the inductioncoil type to serve the engine at the time 01' starting, a magneto to serve the engine after starting and including a primary coil which also serves as the primary coil of said apparatus, a circuit including said primary coil and being normally independent of and tree from connection with the battery circuit, switch means operable to interconnect said circuits and enable current from the battery to fiow through said primary coil, and an automatic device to operate said switch means at the initiation of and for the-duration oi. the starting period of the engine, whereby the able when closed to direct current from the battery to the motor; comprising, a. soft iron core, primary and secondary coils on said core, a circuit including said primary coil, an electromagnet including a core and a stationary energizing coil in circuit with said battery, said stationary coil encompassing the magnet core and effective when energized to magnetize the same, flux distributing members connected to the magnet core and driven by the engine, means driven by the engine to periodically open and close the primary circuit, said members cooperating ,with the first named core to establish flux through said primary coil during its open circuit intervals, and switch means for changing said primary circuit to include said battery, whereby battery current may be directed through the primary coil during its closed circuit intervals, the operation of the last named means being initiated by the closing of the starter switch and the duration of its operation determined by the length of time that the starter switch is closed.

11. Ignition apparatus for an internal combustion engine, having a starting motor, a battery to energize the motor and a starter switch operable when closed to direct current from the battery to the motor; comprising a soft iron core; primary and secondary coils on said core, a circuit including said primary coil, an electromagnet including a core and a stationary energizing coil in circuit with said battery, said stationary coil encompassing the magnet core and effective when energized to magnetize the same, flux distributing members connected to the magnet core and driven by the engine, means driven ,by the engine to periodically open and close the primary circuit, said members cooperating with the first named core to establish flux through said primary coil during its open circuit intervals, and switch means for interrupting the circuit to and discon- 'tinuing the action of said electromagnet and for simultaneouslychanging' said primary circuit to include said battery; whereby battery current may be directed through the primary coil during its closed circuit intervals, the, operation of the last named means being initiated by the closing of the starter switch and the duration of its operation determined by the length of time that the starter switch is closed. I q

KENNETH A. HARMON, TERRENCE G. LOUIS. 

